Air mixing devices such as fans are useful in larger open commercial and industrial building spaces for a variety of reasons. These air mixing devices may be used for recirculating air within the open space defined by the building superstructure (e.g. walls, floor, and ceiling) to provide proper ventilation and reduce vertical temperature stratification of air within the space. This destratifying effect helps maintain a uniform temperature within the structure for optimum comfort of the building occupants and heating/cooling efficiency by circulating warm air which rises and typically occupies the upper elevations with cooler air which sinks and typically occupies the lower elevations within the open space.
In addition to temperature regulation, air mixing devices also serve an additional useful purpose when the building structure serves as a commercial breeding and rearing facility for animals which occupy the space. In the case of a poultry house, for example, levels of ammonia generated by decaying manure may be higher near the floor than at higher elevations within the building structure. To promote healthy air quality within the confined environment and meet the ventilation requirements of the animals, it is further useful therefore to reduce air stratification within such spaces by creating an air circulation pattern which vertically mixes the air for purposes of maintaining uniform air quality throughout the facility.
To further promote good air quality, some air mixing devices may draw fresh replacement outside air into the building. During colder months, air mixing devices may sometimes incorporate heat exchanger elements (e.g. electric resistance, steam, or hot water coils) to heat the outside air prior to discharge into to the open building space. This air tempering approach alone, however, increases energy consumption and operating costs. In addition, the heated hot air may be discharged from the air mixing devices at significantly higher temperature than the room air inside the building and at high velocity which may cause uncomfortable drafts and temperature fluctuations at various locations within the facility.
An air mixing device and system is desired for improved air mixing, distribution, and energy efficiency.